您需要公开的公共属性和用户控件的控件的父页面的构造函数。

You need to expose public properties and a constructor of the UserControl's Controls to the parent page.

假设你的用户控件得到了一个标签：

Say your Usercontrol has got a label:

<asp:Label ID="MyLabel" runat="server" visible="true"/>

在用户控件的codebehind添加此。

In the codebehind of the UserControl add this.

    //Constructor
    public MyUserControl()
    {
        Category = new Label();
    }
    //Exposing the Label
    public Label Category
    {
        get { return this.MyLabel; }
        set { this.MyLabel = value; }
    }

假设你已经添加了用户控件到父页面，它的ID是的MyUserControl。

Assume you have added the UserControl to the parent page and its ID is "MyUserControl".

要在用户控件的标签值设置为使用的东西这样的：

To set the label value of the UserControl to something use this:

MyUserControl.Category.Text=Response.QueryString["categoryname"];//Obviously you would want to encode it first.

如果您需要调用在该用户的codebehind父页面的功能，你将不得不使用委托。我不会推荐，虽然这个方法。

If you need to call functions of the parent page in the UserControl's codebehind, you will have to use delegates. I would not recommend this method though.